If you're a parent or a teacher, you've probably wondered how to balance play and safety for the kids in your care. You don't want to put children in danger, but you also don't want to rob them of the joy of exploration. This week, we talk with psychologist Peter Gray about how this balance has changed — for parents and children alike — and what we can do about it.For more of our reporting on children and parents, check out these classic Hidden Brain episodes:Kinder-GardeningBringing Up Baby